An Asset Catalog is an important piece of any iOS, tvOS, watchOS and macOS application. It lets you organize and manage the different assets used by an app, such as images, sprites, textures, ARKit resources, colors and data.
macOS 10.13 contains a built-in VPN client that natively supports L2TP over IPSec as well as IKEv2.
In this post I describe some parts of the internal architecture of the macOS VPN client. This information will be used in a following article to build an application that replicates some functionalities of the VPN status in the menu bar. This application will also allow to auto connect to an IKEv2 VPN service, something that is currently not possible on macOS.
/usr/lib/libMobileGestalt.dylib is a private library which provides an API to retrieve the capabilities of the iOS device, as well as some runtime information: system version, build version, device type, current status of the airplane mode, …
Let’s say you pick a random pointer. Can we know if it points to a valid Objective-C object? Of course without crashing… Well there is no simple solution. In this post I give a solution for 64-bit architectures. The code provided has only been tested on macOS 10.12.1 and iOS 10.1.1 with the modern Objective-C runtime.
The State Preservation and Restoration system is well documented here: Preserving Your App’s Visual Appearance Across Launches.
But what is not well known is that there is a secret preference to enable debug logs.